A Universal Serial Bus (USB) is a serial bus standard to interface devices with a host computer. The USB was designed to allow many computer peripherals to be connected using a single standardized interface socket and to improve plug and play capabilities by allowing devices to be connected and disconnected without rebooting the computer and turning off the device.
Other convenient features of the USB include providing power to low-consumption devices without a separate external power supply and allowing many devices to be used without requiring manufacturer specific individual device drivers to be installed.
The USB is intended to substitude for serial ports and parallel ports and connects many computer peripherals such as mice, keyboards, PDAs, gamepads, joysticks, scanners, digital cameras, printers, personal media players and flash drives. For many of those devices, the USB has become a standard connection.
USB 2.0 is the most popular USB specification and supports high speed data transmission up to 480 Mbps. However, a more reliable connection technique with a higher transmission rate allows modern digital equipment to transmit greater amounts of data and operate closer to real-time. A USB 3.0 specification was developed to provide a higher data transfer rate than the USB 2.0 specification.
The USB 3.0 data transfer rate (4.8 Gbps) is ten times the USB 2.0 data transfer rate. The USB 3.0 specification is expected to upgrade data transfer efficiency of personal computers, consumer electronics and mobile devices but is not commonly used, yet. The USB 2.0 specification is the dominant USB specification. If the USB 2.0 and USB 3.0 specifications could be combined to form a new interface, the interface would have to comply with the USB 2.0 and USB 3.0 specifications and could be used simultaneously to meet consumers' current and emerging demands.